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Rare variable star 40 EP

HD 13256

RA 32.9330° · Dec 60.7124° · star

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Score breakdown

· 6 badges
40 pts · Rare
Rare 50 pts → Epic
  • Supergiant +18
  • Hot blue B-type star +6
  • Variable star +5
  • Never sets (northern circumpolar) +4
  • Gently variable +4
  • A named variable star +3
Total score 40

10 more points to reach Epic.

Badges

  • Variable star · +5
  • Never sets (northern circumpolar) · +4
  • Hot blue B-type star · +6
  • Supergiant · +18
  • Gently variable · +4
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 3 million times as much light as the Sun. It only looks ordinary because it is so far away.

What it actually is

  • Spectral class. Its spectrum reads B1Ia — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.
  • Where it is in life. It is a luminous supergiant — among the largest and rarest stars in the galaxy.
  • It changes. This star does not hold still: its brightness rises and falls on a rhythm of hours, days or years, either pulsing in size or being eclipsed by a companion.

Find it in the sky

  • How to spot it. At magnitude 8.6 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cassiopeia.
  • Never sets. So far north that from Britain, Canada or northern Europe it never dips below the horizon — it is up every clear night of the year.
  • Best time of year. It stands highest in the middle of the night around October — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out orange (B−V 1) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.

Properties

absmag
-11.38
bv
1.022
constellation
Cas
luminosity
3104559.5881
mag
8.62
name
HD 13256
spect
B1Ia
var amplitude
0.11
var designation
V786
var max
8.566
var min
8.676

About HD 13256

HD 13256 is a rare variable star. It sits in the constellation Cas, shines at apparent magnitude 8.62 and has spectral type B1Ia.

Its spectrum reads B1Ia — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

How to see it

Look for HD 13256 in the constellation Cas. At apparent magnitude 8.62, it is an easy target for binoculars.

Like any astronomical target, HD 13256 is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.

Why HD 13256 is a rare variable star

HD 13256 scores 40 points on Spacedle's rarity scale, which places it in the rare tier. Another 10 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Never sets (northern circumpolar), Hot blue B-type star, Supergiant, Gently variable and A named variable star — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.